chapter 5 Flashcards
what are the two types of electricity supplies
AC and DC
what does AC stand for and why is it called that
it stands for alternating current and its’s called this because the voltage is constantly alternating
how many volts is uk mains suppky
230v
what is the frequency of ac mains supply
50hz
what does dc mean
direct current
what supplies dc current
cells and batteries
describe dc current
a current that is always flowing in the same direction. This is caused by a direct voltage
where in the plug is the live wire , what colour is it and what does it do
it’s brown, it’s on the right by the fuse and it provides the alternating potential difference ( at around 230v)
where in the plug is the neutral wire , what colour is it and what does it do
its blue, on the left of the plug and it completes the circuit, when the circuit is running normally the current flows through the live wire and the neutral wire
where in the plug is the earth wire , what colour is it and what does it do
the earth wire is green and yellow , at the top of the plug and it’s for safety, it stops the casing from becoming live. It doesn’t carry a current except for when there is a fault
what does the total energy transaferred by a apliance depend on
how long its on for and its power
what is the power of a appicance
the energy it transfers per second
what is the equation for the amount of energy transfered by electrical work
Energy transfered(J)=power(W)*time(s)
what does the power rating label tell you
the maximum safe power they can operate at
what does the power rating tell you
the maximum amount of energy transfered per second between the stores
